From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: [PATCH v2 17/17] arm64: KVM: vgic-v3: Do not save ICH_AP0Rn_EL2 for GICv2 emulation Date: Wed, 17 Feb 2016 16:40:49 +0000 Message-ID: <1455727249-24752-18-git-send-email-marc.zyngier@arm.com> References: <1455727249-24752-1-git-send-email-marc.zyngier@arm.com> Cc: Andrew Jones , linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu To: Christoffer Dall Return-path: Received: from foss.arm.com ([217.140.101.70]:33657 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1424077AbcBQQlV (ORCPT ); Wed, 17 Feb 2016 11:41:21 -0500 In-Reply-To: <1455727249-24752-1-git-send-email-marc.zyngier@arm.com> Sender: kvm-owner@vger.kernel.org List-ID: The GICv3 specification mandates that ICH_AP0Rn_EL2 are set to zero when running guests that use the memory mapped registers. This is fine, as we initialize all ICH_AP0Rn_EL2 registers to zero, and restore them on entry. But it also means that we do not need to save these registers on exit. Profit! Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp/vgic-v3-sr.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c index 5f12c57..c2f173d 100644 --- a/arch/arm64/kvm/hyp/vgic-v3-sr.c +++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c @@ -202,14 +202,17 @@ void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu) __gic_v3_set_lr(0, i); } - switch (nr_pri_bits) { - case 7: - cpu_if->vgic_ap0r[3] = read_gicreg(ICH_AP0R3_EL2); - cpu_if->vgic_ap0r[2] = read_gicreg(ICH_AP0R2_EL2); - case 6: - cpu_if->vgic_ap0r[1] = read_gicreg(ICH_AP0R1_EL2); - default: - cpu_if->vgic_ap0r[0] = read_gicreg(ICH_AP0R0_EL2); + /* ICH_AP0Rn is only valid for SRE==1 */ + if (cpu_if->vgic_sre & ICC_SRE_EL1_SRE) { + switch (nr_pri_bits) { + case 7: + cpu_if->vgic_ap0r[3] = read_gicreg(ICH_AP0R3_EL2); + cpu_if->vgic_ap0r[2] = read_gicreg(ICH_AP0R2_EL2); + case 6: + cpu_if->vgic_ap0r[1] = read_gicreg(ICH_AP0R1_EL2); + default: + cpu_if->vgic_ap0r[0] = read_gicreg(ICH_AP0R0_EL2); + } } switch (nr_pri_bits) { -- 2.1.4